63 

 or three Bacillariologists, lo iicime ihem so; But they belong to the 

 Eocene, most likely, as l will show. 



The teritory embraced by the Staked Plain embraces a portion 

 of the state of Texas and the teritory of New Mexico and is a plain, 

 roUing sometimes, but barren. It has been traversed by Prof. Jules 

 Marcov in the northern end in i852, and by Dr. Shumard and otljers 

 in i853 who showed what they considered to be the geology of 

 that section of country. It is in the northwestern part of Texas and 

 eastern part of New Mexico an altitude of 25oo to 4000 feet. The 

 surface is smooth and devoid of forest growth or streams of water 

 if we except the Red River which we wWÌ see drains it in an- 

 cìent times into the Mississippi River. It is in a direct southern 

 continuation and termination of the great plain, as it is called, of 

 the North American continents which extends from British Annerica 

 to the Rio Pecos in Texas, How far into Mexico it goes has not 

 been determined as yet. On the north it includes the Great Plain 

 of Fremont. And this includes the region which I bave called the 

 Occidental Sea and which draìned into the Pacific Ocean by the 

 Colorado and Columbia Rivers, 1 kneed not cali to mind Lakes Bon- 

 neville and Lahontan which bave Bacillarian deposits in them. There 

 are however small ponds or lakelets in the southern part of the 

 Staked Plain which are not fresh but saline and the western part 

 in British America and likewise at the Great Salt Lake in Utah 

 shere the remains of the evaporation of the great sea which once 

 occupied the region. 



Now the geology of the great sea, the Occidental Sea, or when 

 it was formed, with included the plain of British America to Mexico 

 and even into California on^^the other side of the Sierra Nevada 

 mountains, was Eocene, laid down before the Miocene of Monterey, 

 California was formed and the Bacillaria were fresh water, when 

 the Miocene, or rather the Oligocene, which is the earliest than the 

 Miocene, came the Bacillaria were changed by the ocean water to 

 marine, and in this way became Oceanie, We can in this manner ac- 

 count by evolution for the change of some and not of others. Por ali 

 living things were evoluted from some primal germ and to study 

 it out is the task which the naturalist has set for himself. The Ba- 

 cillaria are the first, if we except the Amoeba and the like, and 



